Krnjević K, Lamour Y, MacDonald J F, Nistri A
Can J Physiol Pharmacol. 1979 Sep;57(9):944-56. doi: 10.1139/y79-144.
In cats under Dial, Co, Mn, La, and Sr were injected extracellularly near lumbosacral motoneurones. All tended to improve intracellular recording, but when the membrane potential was initially stable, Mn, and especially Co, had a moderate and reproducible depolarizing action. Both Mn and Co depressed excitatory postsynaptic potentials evoked by dorsal root stimulation. The prominent after-hyperpolarization (a.h.p.), which normally follows the motoneuronal action potential, was consistently and reversibly depressed by Mn and Co (as well as La), the underlying conductance increase being also diminished, but there was no significant reduction in the after-depolarization. By contrast, Sr tended to potentiate the a.h.p., especially when this was depressed by a previous injection of Co or Mn. Unlike the other cations, Co had a marked depressant effect on the action potential, particularly its rate of rise. Since the action potential could be immediately restored by hyperpolarization or by an injection of Sr (in the absence of depolarization), Co may enhance Na inactivation.
在处于 Dial 状态的猫身上，将钴（Co）、锰（Mn）、镧（La）和锶（Sr）细胞外注射到腰骶部运动神经元附近。所有这些元素都倾向于改善细胞内记录，但当膜电位最初稳定时，锰，尤其是钴，具有适度且可重复的去极化作用。锰和钴均抑制由背根刺激诱发的兴奋性突触后电位。运动神经元动作电位之后通常出现的显著的后超极化（a.h.p.），被锰、钴（以及镧）持续且可逆地抑制，其潜在的电导增加也减小，但去极化后电位没有显著降低。相比之下，锶倾向于增强后超极化，尤其是当它被先前注射的钴或锰抑制时。与其他阳离子不同，钴对动作电位有显著的抑制作用，特别是其上升速率。由于通过超极化或注射锶（在无去极化的情况下）可立即恢复动作电位，钴可能增强钠失活。
